Stationary induction apparatus



J. A, SEEI E.

STA-IIONAHY INDUCTION APPARATUS.

APPLICATION man FEB, 15.1921.

Im II, IIIIIIVI Pfam t,

JOHN A. SEEDE. OF SCHENGTADY, NEW YORK, ASSGNOR T0 GNRAL ELECTRC CUM'EANY, A CORPORATION OF NEW YORK.

sfrefrioivanv rnnuc'rron artesanias.

namens.

Specification of Letters Patent.

Patented Nov. t5., tfl.

Application filed February 15, i921. Serial No. 445,112.

To @ZZ i/.fzom it may Concern Be it known that l, JoirN Sri-inn, a citizen ot' the United States, residing at Schenectady, county of Schenectady.y State of Xew York, have invented certain new and useful improvements in Stationary induction ifipparatus, ot which the following is specification. y

lily invention relates to stationary induction apparatus and particularly to transformers provided` with taps. lt has or'its general object an .improved arrangement of parts 'for making the desired tap connections which is rugged, sate and economical;

-.a specific object of my invention being to provide the apparatus with a terminal board for the taps which is arranged in such a manner that.the taps will necessarily always be properly connected.

For many kinds of services supplied with alternating current from stationary7 induction apparatus, it is known to be advantageous to have a definite amount ot relatively high reactance in the circuit especially in the stationary induction apparatus itselt. ThisA is particularly7 true ot transformers adapted to supply current tor welding purposes, especialhv larc welding. The most expeditious way of constructing the apparatus to have this internal reactance is to place some of the turns of the load circuit in poor inductive relation with those ot' the primary circuit. the balance ot the turns in the load circuit being in good inductive relation with those of the primary.

ln .such apparatus'it is frequently desirable vto construct lit so that the internal -reactance may be varied trom time to time to suit the characteristics of the particular load beingserved. Provision to this cud invari-v ably involves the use ot taps in the windings of the load circuit so that the number ot turns in poor inductive relation and in good inductive relation may be varied. Unless special precautions are taken the provision ot a plurality ot taps produces confusion and uncertainty on the part ot the operator as to whether the proper tap connections have been made. v

in the practice ot my invention this uncertainty is entirely avoided for l make use of a terminal board to which 'the taps are led and disposed in such an order that :tor every turn or turns in good inductive relation cut out, a corresponding number ot turns in poorinductive relation are cut in or vice versa.

For a more complete understanding of the nature and objects of 'my invention` reference should be had to the following detailed description taken in connection'with the accompanying drawing in which:

Figure l shows in perspective a trans! former, such as used in arc-welding outtits, orovided with my invention; while Fig. 2 is an explanatory diagram.

Referringnow to the drawings, 10 denotes the core ot' a transformer having windings 11 mounted thereon. mie apparatus, for the class of service indicated, is preferably mounted so as to be portable. To this end it is shown as mounted on a truck 12. The high voltage leads are indicated at 13 while 14 denotes the low voltage leads, having attached thereto electrodes 15; one suitable for welding, the other adapted toA be secured to the joh The tap-leads, which lead from the turns in goodand poor inductive relation with the primary, are shown at 2O and extend to the terminal Yboard 21 disposed on the top of the apparatus so` as to be readily accessible. These leads are secured to conducting terminals 22, Shown on the top of board :21, and are preferably ot a form adapted to be engaged by a connecting' plug or contact-inaking device 23, which is manually manipulated, the same being designed 'to be withdrawn from one pair ot terminals and inserted in another.

rilhese terminals 22 are disposed in parallel rows along the sides ot" the terminal board 2l, as shownin Fig. 2. All terminals in one row (the top row in Fig. 2) are connected to taps t1, t2, t3, etc., which lead successively to the turns in the portion S of the secondary winding which may be cut out and are in good inductive relation with the primary winding l). I

in like manner the terminals in the other row (the bottoni rovv in Fig. 2) are connected to the taps u1, u2, us, etc., vwhich lead successively to the turns in the portion L of Vthe secondary winding which may also be cut out but are in poor inductive relation with the primary winding.

The terminals from the taps are, however, arranged in inverse order, z'. e. the tap t, leading to the iirst turn to ,be ctit outin portion S is disposed opposite the terminal tortap irc i quently desirable to change'the per cent. re-

'd5 leading to the lastturn in Aportion L which may b'e cut out; Similarly the terminal for tap t2 leading to the second turn in portion S which may be cut out is disposed opposite the terminal for tap u, leading to the next to the last turn in portion L, which may be cut out; and so on until the terminal Jfor' tap t5 is disposed opposite the terminal for tap u1.

By this arrangement, the connection making plug 23 which is adaptedto span only one pairof terminals at a time cannot connect together the taps in any combination other than those desired. As shown whenever the plug 23 is moved to cut out one or more turns from the portion of the' winding S, a corresponding numberof turns in the portion L are cut in and vice versa.

It is thus seen that theterminal voltage across .the electrodes l5 is substantially the same for any set of tap connections but theA per cent. of internal reactance is changed with each set of tap connections; since the` turns in the portion L of the secondary winding are highly reactive being in poor inductive relation with the primary. 0n the other hand, theturns of the portion S of the secondary have very low reactance since they are in good inductive relation to the pri- AccordinglyA it is seen that the per cent. reactance is proportional to the ratio of turns in L in series with the load to the turns in S likewise in series with-the load. This arrangement'lhas particular advantages in connection vwith arc-welding Where it is freactance in series with the arc tov get the best operating conditions.

Having now described an embodimentof my invention which is at present the best' meansknown to mefor carrying the same into effect, I would have it understood that this is merely illustrative, and that I d o` not mean to be 'limited thereby to the precise details shown nor-restricted in the choice of recognized equivalents except as defined in my claims hereunto annexed.

What I claim as new and desire to secure by Letters Patent of the United States, is,--

cutting in a corresponding number of turns of the other portion, whereby the percentf reactance is altered withoutaltering the resultant terminal voltage of saidportions.

2. In stationary induction apparatus, the.

tionsand simultaneously cutting in a correv sponding number of turns on the other portion, whereby the per cent. internal react- -ance is altered without altering the resultant terminal voltage of said portions.

3. In stationary induction apparatus, the combination with a core, and two windings disposed thereon in mutual inductive relation, a portion of one winding being in good inductive relation with the other winding and another portion in poor inductive relation, of taps leading to separate turns on said portions, and a terminal board Jfor said taps having av coacting contact-making device, the terminals of said taps being relatively disposed on saidboard so as to yield-a. de-

sired terminal voltage across said portion for every position of said device, each different lcombination with a core, vand two windings disposed thereon in mutual inductive relation, a portionof one winding beingy in good inductive vrelation with the other winding and another portion in poor inductive relation, .of taps leading to separate turns on said portions, and a terminal board for said taps having a contact-making device for its terminals, said terminals being disposed relatively in parallel rows, the tap tothe rst turn of one of4 said portions being opposite the ta-pto the last turn of the other portion, the inverse order being continued successively for all the tap terminals of the turns in the said portions, whereby the 'contact device maybe moved to alter lthe number of active turns in circuit in the respective portions but without altering the total active turns.

In witness whereof, I have hereunto set my hand this 12thdayoi1 February, 1921.

JOHN A. sEEDE., 

